Light Amplification by Stimulated Emission of Radiation, also known as laser, refers to the emission of light from excited atoms. Laser light sources are narrow-band light sources operable to provide colored light. Laser light sources may be desirable because of their long lives, high intensity, and superior collimation. Lasers have a variety of applications, such as laser engraving, laser bonding, laser pointers, photolithography, lighting, LIDAR, surveying, barcode reading, and laser surgery.